Power Purchase Agreements (PPAs) are appealing to cities and towns for several reasons, and frequently because they require no upfront investment by the community. Rather, cost to the community (in addition to non-price factors) is the per kilowatt-hour (kWh) rate for electricity generated by the renewable energy system –the PPA rate. Different developers may propose significantly different PPA rates when responding to the same solicitation. However, PPA rates proposed that are noticeably lower than other bids received may be too good to be true. Inappropriate pricing can compromise the economic viability of these projects and increase risk to the community.

This diagram shows the relationship between parties in a typical, community-scale solar PPA in Massachusetts. Not all PPAs are structured in this manner.

When considering PPA price proposals, it is important to consider both the cost in cents per kilowatt-hour and how financeable the project is at the given PPA rate. PPA projects with PPA rate that is too low may suffer from significant delays as the developer seeks financing from financing parties looking for some return on their investment. Such delays and false starts waste the significant time investments that proponents make to introduce renewable generation in their communities. In addition to lost momentum, incentives and other benefits (e.g., 30% U.S. Treasury Grant) that may be critical to a project’s economics may expire while the developer seeks financing. Ultimately, if the developer is unable to secure financing, the project will likely fall apart.

When examining PPA rates in cents per kilowatt-hour, bid evaluation teams should weigh the benefits of low PPA rates with potential risks:

In contract years 11 and beyond, the PPA rate should be high enough to fund operations and maintenance costs. That is, the PPA provider should have a financial incentive to continue to operate and maintain your system. PPA rates less than $0.02/kWh in years 11-20 should be considered cautiously. If your community entered into such a contract, and the PPA provider abandoned the system, would your community be able to fund maintenance or decommissioning costs?

Low PPA rates may be workable in the context of large projects that will generate significant revenue for the developer, for example, through solar electricity sales to the community and SRECs. However, small and moderately sized projects –especially those with relatively high installed costs (e.g., lengthy interconnection runs, tree stumping required), may not be financeable at a low PPA rate.

Finally, many PPAs contain language that allows for developers to exit the contract prior to commercial operation if they are unable to find financing. Therefore, selecting a PPA rate that makes financial sense to your community, the developer, and their financing partners is important to helping all parties efficiently realize the benefits of renewable energy.